Discussions regarding the scope of state taxing power over nonresident persons have generally focused on one issue — the conditions under which a state can tax such a person without violating the Dormant Commerce Clause. That issue has resulted in significant debate regarding whether physical or economic presences are required to create state power. Unfortunately, however, the discussion has ignored an equally important question — when state power, once it is created, terminates. Notwithstanding the lack of academic or judicial analysis of this issue, many states currently apply “trailing nexus” policies that extend their authority past the cessation of taxpayers’ nexus-creating activities. That concept challenges traditional views of the nexus requirement and seems to directly conflict with the Court’s physical-presence rule. This article analyzes the permissibility and scope of trailing nexus under both physical-presence and economic-nexus paradigms and finds that a disaggregated view of the nexus requirement supports its validity. The article also critiques state’s current trailing-nexus formulations and proposes an economic-latency approach that better comports with the Court’s Dormant Commerce Clause jurisprudence.